1
|
Vialetto J, Ramakrishna SN, Stock S, von Klitzing R, Isa L. Modulating the conformation of microgels by complexation with inorganic nanoparticles. J Colloid Interface Sci 2024; 672:797-804. [PMID: 38870770 DOI: 10.1016/j.jcis.2024.05.163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 06/15/2024]
Abstract
HYPOTHESIS The complexation of microgels with rigid nanoparticles is an effective way to impart novel properties and functions to the resulting hybrid particles for applications such as in optics, catalysis, or for the stabilization of foams/emulsions. The nanoparticles affect the conformation of the polymer network, both in bulk aqueous environments and when the microgels are adsorbed at a fluid interface, in a non-trivial manner by modulating the microgel size, stiffness and apparent contact angle. EXPERIMENTS Here, we provide a detailed investigation, using light scattering, in-situ atomic force microscopy and nano-indentation experiments, of the interaction between poly(N-isopropylacrylamide) microgels and hydrophobized silica nanoparticles after mixing in aqueous suspension to shed light on the network reorganization upon nanoparticle incorporation. FINDINGS The addition of nanoparticles decreases the microgels' bulk swelling and thermal response. When adsorbed at an oil-water interface, a higher ratio of nanoparticles influences the microgel's stiffness as well as their hydrophobic/hydrophilic character by increasing their effective contact angle, consequently modulating the monolayer response upon interfacial compression. Overall, these results provide fundamental understanding on the complex conformation of hybrid microgels in different environments and give inspiration to design new materials where the combination of a soft polymer network and nanoparticles might result in additional functionalities.
Collapse
Affiliation(s)
- Jacopo Vialetto
- Department of Chemistry "Ugo Schiff", University of Florence, via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy; Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland; Consorzio interuniversitario per lo sviluppo dei Sistemi a Grande Interfase (CSGI), via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy.
| | - Shivaprakash N Ramakrishna
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Sebastian Stock
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany
| | - Regine von Klitzing
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| |
Collapse
|
2
|
Centeno SP, Nothdurft K, Klymchenko AS, Pich A, Richtering W, Wöll D. FLIM nanoscopy resolves the structure and preferential adsorption in the co-nonsolvency of PNIPAM microgels in methanol-water. J Colloid Interface Sci 2024; 678:210-220. [PMID: 39243721 DOI: 10.1016/j.jcis.2024.08.235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 08/27/2024] [Accepted: 08/28/2024] [Indexed: 09/09/2024]
Abstract
Polymer microgels are swollen macromolecular networks with a typical size of hundred of nanometers to several microns that show an extraordinary open and responsive architecture to different external stimuli, being therefore important candidates for nanobiotechnology and nanomedical applications such as biocatalysis, sensing and drug delivery. It is therefore crucial to understand the delicate balance of physical-chemical interactions between the polymer backbone and solvent molecules that to a high extent determine their responsivity. In particular, the co-nonsolvency effect of poly(N-isopropylacrylamide) in aqueous alcohols is highly discussed, and there is a disagreement between molecular dynamics (MD) simulations (from literature) of the preferential adsorption of alcohol on the polymer chains and the values obtained by several empirical methods that mostly probe the bulk solvent properties. It is our contention that the most efficacious method for addressing this problem requires a nanoscopic method that can be combined with spectroscopy and record fluorescence spectra and super-resolved fluorescence lifetime images of microgels labeled covalently with the solvatochromic dye Nile Red. By employing this approach, we could simultaneously resolve the structure of sub-micron size objects in the swollen and in the collapsed state and estimate the solvent composition inside of them in - mixtures for two very different polymer architectures. We found an outstanding agreement between the MD simulations and our results that estimate a co-solvent molar fraction excess of approximately 3 with a very flat profile in the lateral direction of the microgel.
Collapse
Affiliation(s)
- S P Centeno
- DWI Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, Aachen, 52074, Germany.
| | - K Nothdurft
- Institute of Physical Chemistry, RWTH-Aachen University, Landoltweg 2, Aachen, 52074, Germany
| | - A S Klymchenko
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CRS, Université de Strasbourg, 74 Route du Rhin, Illkirch, 67401, France
| | - A Pich
- DWI Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, Aachen, 52074, Germany; Functional and Interactive Polymers Institute of Technical and Macromolecular Chemistry, Worringerweg 2, Aachen, 52074, Germany; Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Brightlands Chemelot Campus, Urmonderbaan 22, RD Geleen, 6167, the Netherlands
| | - W Richtering
- DWI Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, Aachen, 52074, Germany; Institute of Physical Chemistry, RWTH-Aachen University, Landoltweg 2, Aachen, 52074, Germany
| | - D Wöll
- Institute of Physical Chemistry, RWTH-Aachen University, Landoltweg 2, Aachen, 52074, Germany.
| |
Collapse
|
3
|
Jana S, Nevskyi O, Höche H, Trottenberg L, Siemes E, Enderlein J, Fürstenberg A, Wöll D. Local Water Content in Polymer Gels Measured with Super-Resolved Fluorescence Lifetime Imaging. Angew Chem Int Ed Engl 2024; 63:e202318421. [PMID: 38165135 DOI: 10.1002/anie.202318421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/03/2024]
Abstract
Water molecules play an important role in the structure, function, and dynamics of (bio-) materials. A direct access to the number of water molecules in nanoscopic volumes can thus give new molecular insights into materials and allow for fine-tuning their properties in sophisticated applications. The determination of the local water content has become possible by the finding that H2 O quenches the fluorescence of red-emitting dyes. Since deuterated water, D2 O, does not induce significant fluorescence quenching, fluorescence lifetime measurements performed in different H2 O/D2 O-ratios yield the local water concentration. We combined this effect with the recently developed fluorescence lifetime single molecule localization microscopy imaging (FL-SMLM) in order to nanoscopically determine the local water content in microgels, i.e. soft hydrogel particles consisting of a cross-linked polymer swollen in water. The change in water content of thermo-responsive microgels when changing from their swollen state at room temperature to a collapsed state at elevated temperature could be analyzed. A clear decrease in water content was found that was, to our surprise, rather uniform throughout the entire microgel volume. Only a slightly higher water content around the dye was found in the periphery with respect to the center of the swollen microgels.
Collapse
Affiliation(s)
- Sankar Jana
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Oleksii Nevskyi
- Third Institute of Physics - Biophysics, Georg August University, 37077, Göttingen, Germany
| | - Hannah Höche
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Leon Trottenberg
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Eric Siemes
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| | - Jörg Enderlein
- Third Institute of Physics - Biophysics, Georg August University, 37077, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Georg August University, 37077, Göttingen, Germany
| | - Alexandre Fürstenberg
- Department of Physical Chemistry and Department of Inorganic and Analytical Chemistry, University of Geneva, 1211, Geneva, Switzerland
| | - Dominik Wöll
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074, Aachen, Germany
| |
Collapse
|
4
|
Wu X, Barner-Kowollik C. Fluorescence-readout as a powerful macromolecular characterisation tool. Chem Sci 2023; 14:12815-12849. [PMID: 38023522 PMCID: PMC10664555 DOI: 10.1039/d3sc04052f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/10/2023] [Indexed: 12/01/2023] Open
Abstract
The last few decades have witnessed significant progress in synthetic macromolecular chemistry, which can provide access to diverse macromolecules with varying structural complexities, topology and functionalities, bringing us closer to the aim of controlling soft matter material properties with molecular precision. To reach this goal, the development of advanced analytical techniques, allowing for micro-, molecular level and real-time investigation, is essential. Due to their appealing features, including high sensitivity, large contrast, fast and real-time response, as well as non-invasive characteristics, fluorescence-based techniques have emerged as a powerful tool for macromolecular characterisation to provide detailed information and give new and deep insights beyond those offered by commonly applied analytical methods. Herein, we critically examine how fluorescence phenomena, principles and techniques can be effectively exploited to characterise macromolecules and soft matter materials and to further unravel their constitution, by highlighting representative examples of recent advances across major areas of polymer and materials science, ranging from polymer molecular weight and conversion, architecture, conformation to polymer self-assembly to surfaces, gels and 3D printing. Finally, we discuss the opportunities for fluorescence-readout to further advance the development of macromolecules, leading to the design of polymers and soft matter materials with pre-determined and adaptable properties.
Collapse
Affiliation(s)
- Xingyu Wu
- School of Chemistry and Physics, Centre for Materials Science, Queensland University of Technology (QUT) 2 George Street Brisbane QLD 4000 Australia
| | - Christopher Barner-Kowollik
- School of Chemistry and Physics, Centre for Materials Science, Queensland University of Technology (QUT) 2 George Street Brisbane QLD 4000 Australia
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| |
Collapse
|
5
|
Saunders C, de Villiers CA, Stevens MM. Single Particle Chemical Characterisation of Nanoformulations for Cargo Delivery. AAPS J 2023; 25:94. [PMID: 37783923 DOI: 10.1208/s12248-023-00855-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/25/2023] [Indexed: 10/04/2023] Open
Abstract
Nanoparticles can encapsulate a range of therapeutics, from small molecule drugs to sensitive biologics, to significantly improve their biodistribution and biostability. Whilst the regulatory approval of several of these nanoformulations has proven their translatability, there remain several hurdles to the translation of future nanoformulations, leading to a high rate of candidate nanoformulations failing during the drug development process. One barrier is that the difficulty in tightly controlling nanoscale particle synthesis leads to particle-to-particle heterogeneity, which hinders manufacturing and quality control, and regulatory quality checks. To understand and mitigate this heterogeneity requires advancements in nanoformulation characterisation beyond traditional bulk methods to more precise, single particle techniques. In this review, we compare commercially available single particle techniques, with a particular focus on single particle Raman spectroscopy, to provide a guide to adoption of these methods into development workflows, to ultimately reduce barriers to the translation of future nanoformulations.
Collapse
Affiliation(s)
- Catherine Saunders
- Department of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Camille A de Villiers
- Department of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Molly M Stevens
- Department of Materials, Department of Bioengineering, and Institute of Biomedical Engineering, Imperial College London, London, SW7 2AZ, UK.
- The Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, OX1 3QU, UK.
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.
- Institute of Biomedical Engineering, University of Oxford, Oxford, OX3 7DQ, UK.
| |
Collapse
|
6
|
Grau-Carbonell A, Hagemans F, Bransen M, Elbers NA, van Dijk-Moes RJA, Sadighikia S, Welling TAJ, van Blaaderen A, van Huis MA. In situ single particle characterization of the themoresponsive and co-nonsolvent behavior of PNIPAM microgels and silica@PNIPAM core-shell colloids. J Colloid Interface Sci 2023; 635:552-561. [PMID: 36608391 DOI: 10.1016/j.jcis.2022.12.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022]
Abstract
Poly(N-isopropylacrylamide) (PNIPAM) microgels and PNIPAM colloidal shells attract continuous strong interest due to their thermoresponsive behavior, as their size and properties can be tuned by temperature. The direct single particle observation and characterization of pure, unlabeled PNIPAM microgels in their native aqueous environment relies on imaging techniques that operate either at interfaces or in cryogenic conditions, thus limiting the observation of their dynamic nature. Liquid Cell (Scanning) Transmission Electron Microscopy (LC-(S) TEM) imaging allows the characterization of materials and dynamic processes such as nanoparticle growth, etching, and diffusion, at nanometric resolution in liquids. Here we show that via a facile post-synthetic in situ polymer labelling step with high-contrast marker core-shell Au@SiO2 nanoparticles (NPs) it is possible to determine the full volume of PNIPAM microgels in water. The labelling allowed for the successful characterization of the thermoresponsive behavior of PNIPAM microgels and core shell silica@PNIPAM hybrid microgels, as well as the co-nonsolvency of PNIPAM in aqueous alcoholic solutions. The interplay between electron beam irradiation and PNIPAM systems in water resulted in irreversible shrinkage due to beam induced water radiolysis products, which in turn also affected the thermoresponsive behavior of PNIPAM. The addition of 2-propanol as radical scavenger improved PNIPAM stability in water under electron beam irradiation.
Collapse
Affiliation(s)
- Albert Grau-Carbonell
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands.
| | - Fabian Hagemans
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands
| | - Maarten Bransen
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands
| | - Nina A Elbers
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands
| | - Relinde J A van Dijk-Moes
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands
| | - Sina Sadighikia
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands
| | - Tom A J Welling
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands
| | - Alfons van Blaaderen
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands.
| | - Marijn A van Huis
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht 3584 CC, the Netherlands.
| |
Collapse
|
7
|
Shaulli X, Rivas-Barbosa R, Bergman MJ, Zhang C, Gnan N, Scheffold F, Zaccarelli E. Probing Temperature Responsivity of Microgels and Its Interplay with a Solid Surface by Super-Resolution Microscopy and Numerical Simulations. ACS NANO 2023; 17:2067-2078. [PMID: 36656959 PMCID: PMC9933603 DOI: 10.1021/acsnano.2c07569] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
Super-resolution microscopy has become a powerful tool to investigate the internal structure of complex colloidal and polymeric systems, such as microgels, at the nanometer scale. An interesting feature of this method is the possibility of monitoring microgel response to temperature changes in situ. However, when performing advanced microscopy experiments, interactions between the particle and the environment can be important. Often microgels are deposited on a substrate, since they have to remain still for several minutes during the experiment. This study uses direct stochastic optical reconstruction microscopy (dSTORM) and advanced coarse-grained molecular dynamics simulations to investigate how individual microgels anchored on hydrophilic and hydrophobic surfaces undergo their volume phase transition with temperature. We find that, in the presence of a hydrophilic substrate, the structure of the microgel is unperturbed and the resulting density profiles quantitatively agree with simulations performed under bulk conditions. Instead, when a hydrophobic surface is used, the microgel spreads at the interface and an interesting competition between the two hydrophobic strengths,monomer-monomer vs monomer-surface,comes into play at high temperatures. The robust agreement between experiments and simulations makes the present study a fundamental step to establish this high-resolution monitoring technique as a platform for investigating more complex systems, these being either macromolecules with peculiar internal structure or nanocomplexes where molecules of interest can be encapsulated in the microgel network and controllably released with temperature.
Collapse
Affiliation(s)
- Xhorxhina Shaulli
- Department
of Physics, University of Fribourg, Chemin du Musée 3, 1700Fribourg, Switzerland
| | - Rodrigo Rivas-Barbosa
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185Roma, Italy
| | - Maxime J. Bergman
- Department
of Physics, University of Fribourg, Chemin du Musée 3, 1700Fribourg, Switzerland
| | - Chi Zhang
- Department
of Physics, University of Fribourg, Chemin du Musée 3, 1700Fribourg, Switzerland
| | - Nicoletta Gnan
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185Roma, Italy
- CNR
Institute of Complex Systems, Uos Sapienza, Piazzale Aldo Moro 2, 00185Roma, Italy
| | - Frank Scheffold
- Department
of Physics, University of Fribourg, Chemin du Musée 3, 1700Fribourg, Switzerland
| | - Emanuela Zaccarelli
- Department
of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185Roma, Italy
- CNR
Institute of Complex Systems, Uos Sapienza, Piazzale Aldo Moro 2, 00185Roma, Italy
| |
Collapse
|
8
|
Vialetto J, Ramakrishna SN, Isa L. In situ imaging of the three-dimensional shape of soft responsive particles at fluid interfaces by atomic force microscopy. SCIENCE ADVANCES 2022; 8:eabq2019. [PMID: 36351021 PMCID: PMC9645722 DOI: 10.1126/sciadv.abq2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 09/23/2022] [Indexed: 05/09/2023]
Abstract
The reconfiguration of individual soft and deformable particles upon adsorption at a fluid interface underpins many aspects of their dynamics and interactions, ultimately regulating the properties of monolayers of relevance for applications. In this work, we demonstrate that atomic force microscopy can be used for the in situ reconstruction of the three-dimensional conformation of model poly(N-isopropylacrylamide) microgels adsorbed at an oil-water interface. We image the particle topography from both sides of the interface to characterize its in-plane deformation and to visualize the occurrence of asymmetric swelling in the two fluids. In addition, the technique enables investigating different fluid phases and particle architectures, as well as studying the effect of temperature variations on particle conformation in situ. We envisage that these results open up an exciting range of possibilities to provide microscopic insights into the single-particle behavior of soft objects at fluid interfaces and into the resulting macroscopic material properties.
Collapse
Affiliation(s)
| | | | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| |
Collapse
|
9
|
Pahari S, Liu S, Lee CH, Akbulut M, Kwon JSI. SAXS-guided unbiased coarse-grained Monte Carlo simulation for identification of self-assembly nanostructures and dimensions. SOFT MATTER 2022; 18:5282-5292. [PMID: 35789362 DOI: 10.1039/d2sm00601d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Recent studies have shown that solvated amphiphiles can form nanostructured self-assemblies called dynamic binary complexes (DBCs) in the presence of ions. Since the nanostructures of DBCs are directly related to their viscoelastic properties, it is important to understand how the nanostructures change under different solution conditions. However, it is challenging to obtain a three-dimensional molecular description of these nanostructures by utilizing conventional experimental characterization techniques or thermodynamic models. To this end, we combined the structural data from small angle X-ray scattering (SAXS) experiments and thermodynamic knowledge from coarse-grained Monte Carlo (CGMC) simulations to identify the detailed three-dimensional nanostructure of DBCs. Specifically, unbiased CGMC simulations are performed with SAXS-guided initial conditions, which aids us to sample accurate nanostructures in a computationally efficient fashion. As a result, an elliptical bilayer nanostructure is obtained as the most probable nanostructure of DBCs whose dimensions are validated by scanning electron microscope (SEM) images. Then, utilizing the obtained molecular model of DBCs, we could also explain the pH tunability of the system. Overall, our results from SAXS-guided unbiased CGMC simulations highlight that using potential energy combined with SAXS data, we can distinguish otherwise degenerate nanostructures resulting from the inherent ambiguity of SAXS patterns.
Collapse
Affiliation(s)
- Silabrata Pahari
- Texas A&M University, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
- Texas A&M Energy Institute, Texas A&M Energy Institute, 1617 Research Pkwy, College Station, TX 77843, USA
| | - Shuhao Liu
- Texas A&M University, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
| | - Chi Ho Lee
- Texas A&M University, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
- Texas A&M Energy Institute, Texas A&M Energy Institute, 1617 Research Pkwy, College Station, TX 77843, USA
| | - Mustafa Akbulut
- Texas A&M University, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
- Texas A&M Energy Institute, Texas A&M Energy Institute, 1617 Research Pkwy, College Station, TX 77843, USA
| | - Joseph Sang-Il Kwon
- Texas A&M University, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
- Texas A&M Energy Institute, Texas A&M Energy Institute, 1617 Research Pkwy, College Station, TX 77843, USA
| |
Collapse
|
10
|
Liu P, Freeley M, Zarbakhsh A, Resmini M. Adsorption of soft NIPAM nanogels at hydrophobic and hydrophilic interfaces: Conformation of the interfacial layers determined by neutron reflectivity. J Colloid Interface Sci 2022; 623:337-347. [PMID: 35594592 DOI: 10.1016/j.jcis.2022.05.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/18/2022] [Accepted: 05/02/2022] [Indexed: 11/25/2022]
Abstract
The application of stimuli-responsive microgels and nanogels in drug delivery, catalysis, sensing, and coatings is restricted currently by the limited understanding of the factors influencing their adsorption dynamics and structural changes at interfaces. We have used neutron reflectivity to resolve, on the Ångström scale, the structure of 5% crosslinked N-isopropylacrylamide nanogels at both hydrophobic and hydrophilic interfaces in situ, as a function of temperature and bulk nanogel concentration. Our results show that the higher flexibility given by the low crosslinker content allows for a more ordered structure and packing. The adsorption of the thermoresponsive nanogels is primarily driven by temperature, more specifically its proximity to its volume phase transition temperature, while concentration plays a secondary role. Hydrophobic interactions drive the conformation of the first layer at the interface, which plays a key role in influencing the overall nanogel structure. The mobility of the first layer at the air-water interface as opposed to the interfacial confinement at the solid (SiC8)-liquid interface, results in a different conformation, a more compact and less deformed packing structure, which ultimately drives the structure of the subsequent layers. The evidence for the different structural conformations determined by the degree of hydrophobicity of the interface provides new knowledge, which is essential for the development of further applications. The key role of hydrophobic interactions in driving adsorption and interfacial behavior was also confirmed by fluid AFM experiments which visualized adherence of the nanogels to SiC8 modified surfaces.
Collapse
Affiliation(s)
- Pengfei Liu
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Mark Freeley
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Ali Zarbakhsh
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| | - Marina Resmini
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| |
Collapse
|
11
|
Near-infrared excitation/emission microscopy with lanthanide-based nanoparticles. Anal Bioanal Chem 2022; 414:4291-4310. [PMID: 35312819 DOI: 10.1007/s00216-022-03999-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/23/2022] [Accepted: 02/28/2022] [Indexed: 12/26/2022]
Abstract
Near-infrared optical imaging offers some advantages over conventional imaging, such as deeper tissue penetration, low or no autofluorescence, and reduced tissue scattering. Lanthanide-doped nanoparticles (LnNPs) have become a trend in the field of photoactive nanomaterials for optical imaging due to their unique optical features and because they can use NIR light as excitation and/or emission light. This review is focused on NaREF4 NPs and offers an overview of the state-of-the-art investigation in their use as luminophores in optical microscopy, time-resolved imaging, and super-resolution nanoscopy based on, or applied to, LnNPs. Secondly, whenever LnNPs are combined with other nanomaterial or nanoparticle to afford nanohybrids, the characterization of their physical and chemical properties is of current interest. In this context, the latest trends in optical microscopy and their future perspectives are discussed.
Collapse
|
12
|
Witt MU, Landers J, Hinrichs S, Salamon S, Kopp J, Hankiewicz B, Wende H, von Klitzing R. Magnetic response of CoFe 2O 4 nanoparticles confined in a PNIPAM microgel network. SOFT MATTER 2022; 18:1089-1099. [PMID: 35037679 DOI: 10.1039/d1sm01597d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The paper addresses coupling of magnetic nanoparticles (MNPs) with the polymer matrix of temperature-sensitive microgels and their response to magnetic fields. Therefore, CoFe2O4@CA (CA = citric acid) NPs are embedded within N-isopropylacrylamid (NIPAM) based microgels. The volume phase transition (VPT) of the magnetic microgels and the respective pure microgels is studied by dynamic light scattering and electrophoretic mobility measurements. The interaction between MNPs and microgel network is studied via magnetometry and AC-susceptometry using a superconducting quantum interference device (SQUID). The data show a significant change of the magnetic properties by crossing the VPT temperature (VPTT). The change is related to the increased confinement of the MNP due to the shrinking of the microgels. Modifying the microgel with hydrophobic allyl mercaptan (AM) affects the swelling ability and the magnetic response, i.e. the coupling of MNPs with the polymer matrix. Modeling the AC-susceptibility data results in an effective size distribution. This distribution represents the varying degree of constraint in MNP rotation and motion by the microgel network. These findings help to understand the interaction between MNPs and the microgel matrix to design multi responsive systems with tunable particle matrix coupling strength for future applications.
Collapse
Affiliation(s)
- Marcus U Witt
- Department of Physics, Soft Matter at Interfaces, Technical University Darmstadt, Hochschulstraße 8, 64287 Darmstadt, Germany.
| | - Joachim Landers
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Stephan Hinrichs
- Institute of Physical Chemistry, Hamburg University, Grindelallee 117, 20146 Hamburg, Germany
| | - Soma Salamon
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Juri Kopp
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Birgit Hankiewicz
- Institute of Physical Chemistry, Hamburg University, Grindelallee 117, 20146 Hamburg, Germany
| | - Heiko Wende
- Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Regine von Klitzing
- Department of Physics, Soft Matter at Interfaces, Technical University Darmstadt, Hochschulstraße 8, 64287 Darmstadt, Germany.
| |
Collapse
|
13
|
Ponomareva E, Tadgell B, Hildebrandt M, Krüsmann M, Prévost S, Mulvaney P, Karg M. The fuzzy sphere morphology is responsible for the increase in light scattering during the shrinkage of thermoresponsive microgels. SOFT MATTER 2022; 18:807-825. [PMID: 34939641 DOI: 10.1039/d1sm01473k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Thermoresponsive microgels undergo a volume phase transition from a swollen state under good solvent conditions to a collapsed state under poor solvent conditions. The most prominent examples of such responsive systems are based on poly-(N-isopropylacrylamide). When cross-linked with N,N'-methylenebisacrylamide, such microgels typically possess a fuzzy-spherelike morphology with a higher cross-linked core and a loosely cross-linked fuzzy shell. Despite the efforts devoted to understanding the internal structure of microgels and their kinetics during collapse/swelling, the origins of the accompanying changes in light scattering intensity have barely been addressed. In this work, we study core-shell microgels that contain small gold nanoparticle cores with microgel shells of different thicknesses and cross-linker densities. All microgels are small enough to fulfill the Rayleigh-Debye-Gans criterion at all stages of swelling. Due to the high X-ray contrast of the gold cores, we can use absolute intensity small-angle X-ray scattering to determine the number density in the dilute dispersions. This allows us to extract polymer volume fractions of the microgels at different stages of swelling from form factor analysis of small-angle neutron scattering data. We match our findings to results from temperature-dependent absorbance measurements. The increase in absorbance during the shrinkage of the microgels is related to the transition from fuzzy spheres to hard sphere-like scattering objects with a rather homogeneous density profile. We provide a first attempt to model experimental spectra using finite difference time domain simulations that take into account the structural changes during the volume phase transition. Our findings significantly contribute to the understanding of the optical properties of thermoresponsive microgels. Further, we provide polymer volume fractions and microgel refractive indices as a function of the swelling state.
Collapse
Affiliation(s)
- Ekaterina Ponomareva
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
| | - Ben Tadgell
- ARC Centre of Excellence in Exciton Science, The University of Melbourne, School of Chemistry, Parkville, VIC 3010, Australia
| | - Marco Hildebrandt
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
| | - Marcel Krüsmann
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
| | - Sylvain Prévost
- Large Scale Structures, Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble Cedex 9, France
| | - Paul Mulvaney
- ARC Centre of Excellence in Exciton Science, The University of Melbourne, School of Chemistry, Parkville, VIC 3010, Australia
| | - Matthias Karg
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstrase 1, D-40225 Düsseldorf, Germany.
| |
Collapse
|
14
|
Kenath GS, Karanastasis AA, Ullal CK. Super-Resolution Imaging of Spatial Heterogeneities in Model Thermosensitive Hydrogels with Implications for Their Origins. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gopal S. Kenath
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
| | - Apostolos A. Karanastasis
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
| | - Chaitanya K. Ullal
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States
| |
Collapse
|
15
|
Scotti A. Characterization of the volume fraction of soft deformable microgels by means of small-angle neutron scattering with contrast variation. SOFT MATTER 2021; 17:5548-5559. [PMID: 33978056 DOI: 10.1039/d1sm00277e] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The volume occupied by colloids in a suspension - namely the volume fraction - is the thermodynamic variable that determines the phase behavior of these systems. While for hard incompressible spheres this quantity is well defined, for soft compressible colloids such as microgels - polymeric crosslinked networks swollen in a good solvent - the determination of the real volume occupied by these particles in solution is particularly challenging. This fact depends on two aspects: first the surface and, therefore, the volume of the microgels is hard to define properly given their external fuzziness; second, microgels can osmotically deswell, deform or interpenetrate their neighbors, i.e. change their shape and size depending on the solution concentration. Here, the form factors of few hydrogenated microgels embedded in a matrix of deuterated but otherwise identical microgels are measured using small-angle neutron scattering with contrast variation. From the analysis of the scattering data, the variation of the volume of the microgels as a function of concentration is obtained and used to calculate the real microgel volume fraction in solution. Soft neutral microgels are shown to facet already at low concentrations while in contrast, harder microgels maintain their shape and change their volume.
Collapse
Affiliation(s)
- Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056, Aachen, Germany.
| |
Collapse
|
16
|
Affiliation(s)
- Yuichiro Nishizawa
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Kenshiro Honda
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
- Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| |
Collapse
|
17
|
Colloidal and polymeric contributions to the yielding of dense microgel suspensions. J Colloid Interface Sci 2021; 587:437-445. [DOI: 10.1016/j.jcis.2020.11.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/06/2020] [Accepted: 11/25/2020] [Indexed: 11/21/2022]
|
18
|
Tan SF, Reidy K, Klein J, Pinkowitz A, Wang B, Ross FM. Real-time imaging of nanoscale electrochemical Ni etching under thermal conditions. Chem Sci 2021; 12:5259-5268. [PMID: 34163761 PMCID: PMC8179569 DOI: 10.1039/d0sc06057g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The ability to vary the temperature of an electrochemical cell provides opportunities to control reaction rates and pathways and to drive processes that are inaccessible at ambient temperature. Here, we explore the effect of temperature on electrochemical etching of Ni–Pt bimetallic nanoparticles. To observe the process at nanoscale resolution we use liquid cell transmission electron microscopy with a modified liquid cell that enables simultaneous heating and biasing. By controlling the cell temperature, we demonstrate that the reaction rate and dissolution potential of the electrochemical Ni etching process can be changed. The in situ measurements suggest that the destabilization of the native nickel oxide layer is the slow step prior to subsequent fast Ni removal in the electrochemical Ni dissolution process. These experiments highlight the importance of in situ structural characterization under electrochemical and thermal conditions as a strategy to provide deeper insights into nanomaterial transformations as a function of temperature and potential. The combination of electrochemical analysis, temperature control and in situ TEM imaging directly probes the etching of Ni from bimetallic Ni–Pt nanoparticles.![]()
Collapse
Affiliation(s)
- Shu Fen Tan
- Department of Materials Science and Engineering, Massachusetts Institute of Technology MA 02139 Cambridge USA
| | - Kate Reidy
- Department of Materials Science and Engineering, Massachusetts Institute of Technology MA 02139 Cambridge USA
| | - Julian Klein
- Department of Materials Science and Engineering, Massachusetts Institute of Technology MA 02139 Cambridge USA
| | - Ainsley Pinkowitz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology MA 02139 Cambridge USA
| | - Baoming Wang
- Department of Materials Science and Engineering, Massachusetts Institute of Technology MA 02139 Cambridge USA
| | - Frances M Ross
- Department of Materials Science and Engineering, Massachusetts Institute of Technology MA 02139 Cambridge USA
| |
Collapse
|
19
|
Schulte MF, Bochenek S, Brugnoni M, Scotti A, Mourran A, Richtering W. Stiffness Tomography of Ultra-Soft Nanogels by Atomic Force Microscopy. Angew Chem Int Ed Engl 2021; 60:2280-2287. [PMID: 33459462 PMCID: PMC7898630 DOI: 10.1002/anie.202011615] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Indexed: 01/02/2023]
Abstract
The softness of nanohydrogels results in unique properties and recently attracted tremendous interest due to the multi-functionalization of interfaces. Herein, we study extremely soft temperature-sensitive ultra-low cross-linked (ULC) nanogels adsorbed to the solid/water interface by atomic force microscopy (AFM). The ultra-soft nanogels seem to disappear in classical imaging modes since a sharp tip fully penetrates these porous networks with very low forces in the range of steric interactions (ca. 100 pN). However, the detailed evaluation of Force Volume mode measurements allows us to resolve their overall shape and at the same time their internal structure in all three dimensions. The nanogels exhibit an extraordinary disk-like and entirely homogeneous but extremely soft structure-even softer than polymer brushes. Moreover, the temperature-sensitive nanogels can be switched on demand between the ultra-soft and a very stiff state.
Collapse
Affiliation(s)
| | - Steffen Bochenek
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
| | - Monia Brugnoni
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
| | - Andrea Scotti
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
| | - Ahmed Mourran
- DWI—Leibniz Institute for Interactive MaterialsForckenbeckstr. 5052056AachenGermany
| | - Walter Richtering
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
- DWI—Leibniz Institute for Interactive MaterialsForckenbeckstr. 5052056AachenGermany
| |
Collapse
|
20
|
Bochenek S, McNamee CE, Kappl M, Butt HJ, Richtering W. Interactions between a responsive microgel monolayer and a rigid colloid: from soft to hard interfaces. Phys Chem Chem Phys 2021; 23:16754-16766. [PMID: 34319323 DOI: 10.1039/d1cp01703a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Responsive poly-N-isopropylacrylamide-based microgels are commonly used as model colloids with soft repulsive interactions. It has been shown that the microgel-microgel interaction in solution can be easily adjusted by varying the environmental parameters, e.g., temperature, pH, or salt concentration. Furthermore, microgels readily adsorb to liquid-gas and liquid-liquid interfaces forming responsive foams and emulsions that can be broken on-demand. In this work, we explore the interactions between microgel monolayers at the air-water interface and a hard colloid in the water. Force-distance curves between the monolayer and a silica particle were measured with the Monolayer Particle Interaction Apparatus. The measurements were conducted at different temperatures and lateral compressions, i.e., different surface pressures. The force-distance approach curves display long-range repulsive forces below the volume phase transition temperature of the microgels. Temperature and lateral compression reduce the stiffness of the monolayer. The adhesion increases with temperature and decreases with a lateral compression of the monolayer. When compressed laterally, the interactions between the microgels are hardly affected by temperature, as the directly adsorbed microgel fractions are nearly insensitive to temperature. In contrast, our findings show that the temperature-dependent swelling of the microgel fractions in the aqueous phase strongly influences the interaction with the probe. This is explained by a change in the microgel monolayer from a soft to a hard repulsive interface.
Collapse
Affiliation(s)
- Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | | | | | | | | |
Collapse
|
21
|
Scotti A, Pelaez-Fernandez M, Gasser U, Fernandez-Nieves A. Osmotic pressure of suspensions comprised of charged microgels. Phys Rev E 2021; 103:012609. [PMID: 33601513 DOI: 10.1103/physreve.103.012609] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
We determine the osmotic pressure of microgel suspensions using membrane osmometry and dialysis, for microgels with different softnesses. Our measurements reveal that the osmotic pressure of solutions of both ionic and neutral microgels is determined by the free ions that leave the microgel periphery to maximize their entropy and not by the translational degrees of freedom of the microgels themselves. Furthermore, up to a given concentration it is energetically favorable for the microgels to maintain a constant volume without appreciable deswelling. The concentration where deswelling starts weakly depends on the crosslinker concentration, which affects the microgel dimension; we explain this by considering the dependence of the osmotic pressure and the microgel bulk modulus on the particle size.
Collapse
Affiliation(s)
- A Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| | - M Pelaez-Fernandez
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
| | - U Gasser
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - A Fernandez-Nieves
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
- ICREA-Institucio Catalana de Recerca i Estudis Avancats, 08010 Barcelona, Spain
- School of Physics, Georgia Institute of Technology, Atlanta, 30332 Georgia, USA
| |
Collapse
|
22
|
Schulte MF, Bochenek S, Brugnoni M, Scotti A, Mourran A, Richtering W. Stiffness Tomography of Ultra‐Soft Nanogels by Atomic Force Microscopy. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011615] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- M. Friederike Schulte
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Steffen Bochenek
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Monia Brugnoni
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Andrea Scotti
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Ahmed Mourran
- DWI—Leibniz Institute for Interactive Materials Forckenbeckstr. 50 52056 Aachen Germany
| | - Walter Richtering
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
- DWI—Leibniz Institute for Interactive Materials Forckenbeckstr. 50 52056 Aachen Germany
| |
Collapse
|
23
|
|
24
|
Microgel Particles with Distinct Morphologies and Common Chemical Compositions: a Unified Description of the Responsivity to Temperature and Osmotic Stress. Gels 2020; 6:gels6040034. [PMID: 33081416 PMCID: PMC7709680 DOI: 10.3390/gels6040034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/13/2020] [Accepted: 10/16/2020] [Indexed: 11/30/2022] Open
Abstract
Poly(N-isopropylacrylamide) (PNIPAM) hydrogel microparticles with different core–shell morphologies have been designed, while maintaining an unvaried chemical composition: a morphology with (i) an un-crosslinked core with a crosslinked shell of PNIPAM chains and (ii) PNIPAM chains crosslinked to form the core with a shell consisting of tethered un-crosslinked PNIPAM chains to the core. Both morphologies with two different degrees of crosslinking have been assessed by confocal microscopy and tested with respect to their temperature responsivity and deformation by applying an osmotic stress. The thermal and mechanical behavior of these architectures have been framed within a Flory–Rehner modified model in order to describe the microgel volume shrinking occurring as response to a temperature increase or an osmotic perturbation. This study provides a background for assessing to what extent the mechanical features of the microgel particle surface affect the interactions occurring at the interface of a microgel particle with a cell, in addition to the already know ligand/receptor interaction. These results have direct implications in triggering a limited phagocytosis of microdevices designed as injectable drug delivery systems.
Collapse
|
25
|
Dockendorff J, Mourran A, Gumerov RA, Potemkin II, Möller M, Gauthier M. Metal Coordination Induces Phase Segregation in Amphipolar Arborescent Copolymers with a Core-Shell-Corona Architecture. Macromolecules 2020; 53:8108-8122. [PMID: 35516458 PMCID: PMC9062874 DOI: 10.1021/acs.macromol.0c00778] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/07/2020] [Indexed: 01/08/2023]
Abstract
Arborescent copolymers with a core-shell-corona (CSC) architecture were synthesized and the topology of the molecules was challenged (constrained) through intramolecular interactions, resulting in phase separation breaking the symmetry of radial density. The inner poly(2-vinylpyridine) shell of these arborescent polystyrene-g-[poly(2-vinylpyridine)-b-polystyrene] molecules can self-assemble by binding metallic salts and acids in apolar and intermediate-polarity solvents. Upon loading with HAuCl4, the characteristics of the polymer templates govern the "loading sites" of the metal within the molecules. Unique morphologies were observed for the metal-loaded G0-G4 arborescent copolymers investigated, namely, spherical, toroidal, raspberry-like, spherical nanocage, and a new worm-in-sphere morphology. The reason for the emergence of such morphologies is the interplay among intramolecular interactions of unlike polymer segments, solvent selectivity, the entropic elasticity of the arborescent substrate, and phase segregation induced by coordination with the charged metallic species. Meanwhile, the stability of the arborescent molecules against aggregation provides intramolecular phase segregation with imposed "confined" geometry and thus leads to nonconventional morphologies. Furthermore, the size of the arborescent molecules is much smaller than that of other known particles (droplets) serving as confined geometries. Computer simulations were used to model the mesostructure of the arborescent copolymers, to demonstrate the influence of solvent selectivity, together with HAuCl4 loading, on the evolution of the morphology of the macromolecules.
Collapse
Affiliation(s)
- Jason Dockendorff
- Department
of Chemistry, Institute for Polymer Research and Waterloo Institute
for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Ahmed Mourran
- DWI-Leibniz
Institute for Interactive Materials, Forckenbeckstr. 50, D-52056 Aachen, Germany
| | - Rustam A. Gumerov
- DWI-Leibniz
Institute for Interactive Materials, Forckenbeckstr. 50, D-52056 Aachen, Germany
- Physics
Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
| | - Igor I. Potemkin
- DWI-Leibniz
Institute for Interactive Materials, Forckenbeckstr. 50, D-52056 Aachen, Germany
- Physics
Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
- South
Ural State University (National Research University), Chelyabinsk 454080, Russian Federation
| | - Martin Möller
- DWI-Leibniz
Institute for Interactive Materials, Forckenbeckstr. 50, D-52056 Aachen, Germany
| | - Mario Gauthier
- Department
of Chemistry, Institute for Polymer Research and Waterloo Institute
for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
26
|
Qiang Z, Wang M. 100th Anniversary of Macromolecular Science Viewpoint: Enabling Advances in Fluorescence Microscopy Techniques. ACS Macro Lett 2020; 9:1342-1356. [PMID: 35638626 DOI: 10.1021/acsmacrolett.0c00506] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the past few decades there has been a revolution in the field of optical microscopy with emerging capabilities such as super-resolution and single-molecule fluorescence techniques. Combined with the classical advantages of fluorescence imaging, such as chemical labeling specificity, and noninvasive sample preparation and imaging, these methods have enabled significant advances in our polymer community. This Viewpoint discusses several of these capabilities and how they can uniquely offer information where other characterization techniques are limited. Several examples are highlighted that demonstrate the ability of fluorescence microscopy to understand key questions in polymer science such as single-molecule diffusion and orientation, 3D nanostructural morphology, and interfacial and multicomponent dynamics. Finally, we briefly discuss opportunities for further advances in techniques that may allow them to make an even greater contribution in polymer science.
Collapse
Affiliation(s)
- Zhe Qiang
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
| | - Muzhou Wang
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| |
Collapse
|
27
|
Wrede O, Bergmann S, Hannappel Y, Hellweg T, Huser T. Smart microgels investigated by super-resolution fluorescence microscopy: influence of the monomer structure on the particle morphology. SOFT MATTER 2020; 16:8078-8084. [PMID: 32789349 DOI: 10.1039/d0sm00597e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In a recent publication [Bergmann et al. Phys. Chem. Chem. Phys., 2018, 20, 5074-5083] we presented a method which enables to investigate the morphology of microgels by superresolution fluorescence microscopy. Here, this method is applied to three microgel species, based on N-isopropylmethacrylamide (NIPMAM), N-n-propylacrylamide (NNPAM) and N-n-propylmethacrylamide (NNPMAM)) with 5, 7.5 and 10 mol% cross-linker, respectively. Super-resolution microscopy reveals differences of the network morphology of the synthesized particles showing the importance of the monomer structure.
Collapse
Affiliation(s)
- Oliver Wrede
- Biomolecular Photonics, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
| | | | | | | | | |
Collapse
|
28
|
Scheffold F. Pathways and challenges towards a complete characterization of microgels. Nat Commun 2020; 11:4315. [PMID: 32887886 PMCID: PMC7473851 DOI: 10.1038/s41467-020-17774-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 07/20/2020] [Indexed: 01/07/2023] Open
Abstract
Due to their controlled size, sensitivity to external stimuli, and ease-of-use, microgel colloids are unique building blocks for soft materials made by crosslinking polymers on the micrometer scale. Despite the plethora of work published, many questions about their internal structure, interactions, and phase behavior are still open. The reasons for this lack of understanding are the challenges arising from the small size of the microgel particles, complex pairwise interactions, and their solvent permeability. Here we describe pathways toward a complete understanding of microgel colloids based on recent experimental advances in nanoscale characterization, such as super-resolution microscopy, scattering methods, and modeling.
Collapse
Affiliation(s)
- Frank Scheffold
- Department of Physics, University of Fribourg, Chemin du Musée 3, 1700, Fribourg, Switzerland.
| |
Collapse
|
29
|
Watanabe T, Nishizawa Y, Minato H, Song C, Murata K, Suzuki D. Hydrophobic Monomers Recognize Microenvironments in Hydrogel Microspheres during Free-Radical-Seeded Emulsion Polymerization. Angew Chem Int Ed Engl 2020; 59:8849-8853. [PMID: 32232936 DOI: 10.1002/anie.202003493] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 03/25/2020] [Indexed: 11/10/2022]
Abstract
The three-dimensional structure of nanocomposite microgels was precisely determined by cryo-electron micrography. Several nanocomposite microgels that differ with respect to their nanocomposite structure, which were obtained from seeded emulsion polymerization in the presence of microgels, were used as model nanocomposite materials for cryo-electron micrography. The obtained three-dimensional segmentation images of these nanocomposite microgels provide important insights into the interactions between the hydrophobic monomers and the microgels, that is, hydrophobic styrene monomers recognize molecular-scale differences in polarity within the microgels during the emulsion polymerization. This result led to the formation of unprecedented multi-layered nanocomposite microgels, which promise substantial potential in colloidal applications.
Collapse
Affiliation(s)
- Takumi Watanabe
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan
| | - Yuichiro Nishizawa
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan
| | - Haruka Minato
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan
| | - Chihong Song
- Department National Institute for Physiological Sciences, 38 Nishigonaka, Okazaki, Aichi, 444-8585, Japan
| | - Kazuyoshi Murata
- Department National Institute for Physiological Sciences, 38 Nishigonaka, Okazaki, Aichi, 444-8585, Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan.,Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan
| |
Collapse
|
30
|
Dutta C, Bishop LDC, Zepeda O J, Chatterjee S, Flatebo C, Landes CF. Imaging Switchable Protein Interactions with an Active Porous Polymer Support. J Phys Chem B 2020; 124:4412-4420. [PMID: 32441098 DOI: 10.1021/acs.jpcb.0c01807] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mechanistic details about how local physicochemistry of porous interfaces drives protein transport mechanisms are necessary to optimize biomaterial applications. Cross-linked hydrogels made of stimuli-responsive polymers have potential for active protein capture and release through tunable steric and chemical transformations. Simultaneous monitoring of dynamic changes in both protein transport and interfacial polymer structure is an experimental challenge. We use single-particle tracking (SPT) and fluorescence correlation spectroscopy Super-resolution Optical Fluctuation Imaging (fcsSOFI) to relate the switchable changes in size and structure of a pH-responsive hydrogel to the interfacial transport properties of a model protein, lysozyme. SPT analysis reveals the reversible switching of protein transport dynamics in and at the hydrogel polymer in response to pH changes. fcsSOFI allows us to relate tunable heterogeneity of the hydrogels and pores to reversible changes in the distribution of confined diffusion and adsorption/desorption. We find that physicochemical heterogeneity of the hydrogels dictates protein confinement and desorption dynamics, particularly at pH conditions in which the hydrogels are swollen.
Collapse
Affiliation(s)
- Chayan Dutta
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Logan D. C. Bishop
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Jorge Zepeda O
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Sudeshna Chatterjee
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Charlotte Flatebo
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Applied Physics Program, Rice University, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, HoustonTexas 77005, United States
| |
Collapse
|
31
|
Dutta C, Bishop LDC, Zepeda O J, Chatterjee S, Flatebo C, Landes CF. Imaging Switchable Protein Interactions With an Active Porous Polymer Support. J Phys Chem A 2020. [DOI: 10.1021/acs.jpca.0c01807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
32
|
Watanabe T, Nishizawa Y, Minato H, Song C, Murata K, Suzuki D. Hydrophobic Monomers Recognize Microenvironments in Hydrogel Microspheres during Free‐Radical‐Seeded Emulsion Polymerization. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Takumi Watanabe
- Graduate School of Textile Science & Technology Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
| | - Yuichiro Nishizawa
- Graduate School of Textile Science & Technology Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
| | - Haruka Minato
- Graduate School of Textile Science & Technology Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
| | - Chihong Song
- Department National Institute for Physiological Sciences 38 Nishigonaka Okazaki Aichi 444-8585 Japan
| | - Kazuyoshi Murata
- Department National Institute for Physiological Sciences 38 Nishigonaka Okazaki Aichi 444-8585 Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
- Research Initiative for Supra-Materials Interdisciplinary Cluster for Cutting Edge Research Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
| |
Collapse
|
33
|
Oberdisse J, Hellweg T. Recent advances in stimuli-responsive core-shell microgel particles: synthesis, characterisation, and applications. Colloid Polym Sci 2020. [DOI: 10.1007/s00396-020-04629-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AbstractInspired by the path followed by Matthias Ballauff over the past 20 years, the development of thermosensitive core-shell microgel structures is reviewed. Different chemical structures, from hard nanoparticle cores to double stimuli-responsive microgels have been devised and successfully implemented by many different groups. Some of the rich variety of these systems is presented, as well as some recent progress in structural analysis of such microstructures by small-angle scattering of neutrons or X-rays, including modelling approaches. In the last part, again following early work by the group of Matthias Ballauff, applications with particular emphasis on incorporation of catalytic nanoparticles inside core-shell structures—stabilising the nanoparticles and granting external control over activity—will be discussed, as well as core-shell microgels at interfaces.
Collapse
|
34
|
Cors M, Wiehemeier L, Wrede O, Feoktystov A, Cousin F, Hellweg T, Oberdisse J. Contrast variation SANS measurement of shell monomer density profiles of smart core-shell microgels. SOFT MATTER 2020; 16:1922-1930. [PMID: 31995091 DOI: 10.1039/c9sm02036e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The radial density profile of deuterated poly(N,n-propyl acrylamide) shell monomers within core-shell microgels has been studied by small-angle neutron scattering in order to shed light on the origin of their linear thermally-induced swelling. The poly(N-isopropyl methacrylamide) core monomers have been contrast-matched by the H2O/D2O solvent mixture, and the intensity thus provides a direct measurement of the spatial distribution of the shell monomers. Straightforward modelling shows that their structure does not correspond to the expected picture of a well-defined external shell. A multi-shell model solved by a reverse Monte Carlo approach is then applied to extract the monomer density as a function of temperature and of the core crosslinking. It is found that most shell monomers fill the core at high temperatures approaching synthesis conditions of collapsed particles, forming only a dilute corona. As the core monomers tend to swell at lower temperatures, a skeleton of insoluble shell monomers hinders swelling, inducing the progressive linear thermoresponse.
Collapse
Affiliation(s)
- Marian Cors
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany. and Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, 34095 Montpellier, France.
| | - Lars Wiehemeier
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Oliver Wrede
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Artem Feoktystov
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science JCNS at Heinz Maier-Leibnitz Zentrum MLZ, 85748 Garching, Germany
| | - Fabrice Cousin
- Laboratoire Léon Brillouin, UMR 12 CEA/CNRS, CEA Saclay, 91191 Gif Sur Yvette, France
| | - Thomas Hellweg
- Department of Physical and Biophysical Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany.
| | - Julian Oberdisse
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, 34095 Montpellier, France.
| |
Collapse
|
35
|
Enhanced catalyst performance through compartmentalization exemplified by colloidal l-proline modified microgel catalysts. J Colloid Interface Sci 2020; 559:76-87. [DOI: 10.1016/j.jcis.2019.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/29/2019] [Accepted: 10/03/2019] [Indexed: 01/28/2023]
|
36
|
Otto P, Bergmann S, Sandmeyer A, Dirksen M, Wrede O, Hellweg T, Huser T. Resolving the internal morphology of core-shell microgels with super-resolution fluorescence microscopy. NANOSCALE ADVANCES 2020; 2:323-331. [PMID: 36134006 PMCID: PMC9416983 DOI: 10.1039/c9na00670b] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
We investigate the internal morphology of smart core-shell microgels by super-resolution fluorescence microscopy exploiting a combination of 3D single molecule localization and structured illumination microscopy utilizing freely diffusing fluorescent dyes. This approach does not require any direct chemical labeling and does not perturb the network structure of these colloidal gels. Hence, it allows us to study the morphology of the particles with very high precision. We found that the structure of the core-forming seed particles is drastically changed by the second synthesis step necessary for making the shell, resulting in a core region with highly increased dye localization density. The present work shows that super-resolution microscopy has great potential with respect to the study of soft colloidal systems.
Collapse
Affiliation(s)
- Pia Otto
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | | | | | - Maxim Dirksen
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | - Oliver Wrede
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | - Thomas Hellweg
- Physical and Biophysical Chemistry, Bielefeld University Germany
| | - Thomas Huser
- Biomolecular Photonics, Bielefeld University Germany
| |
Collapse
|
37
|
Xu W, Rudov A, Oppermann A, Wypysek S, Kather M, Schroeder R, Richtering W, Potemkin II, Wöll D, Pich A. Synthesis of Polyampholyte Janus-like Microgels by Coacervation of Reactive Precursors in Precipitation Polymerization. Angew Chem Int Ed Engl 2020; 59:1248-1255. [PMID: 31664769 PMCID: PMC6973257 DOI: 10.1002/anie.201910450] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/30/2019] [Indexed: 01/20/2023]
Abstract
Controlling the distribution of ionizable groups of opposite charge in microgels is an extremely challenging task, which could open new pathways to design a new generation of stimuli-responsive colloids. Herein, we report a straightforward approach for the synthesis of polyampholyte Janus-like microgels, where ionizable groups of opposite charge are located on different sides of the colloidal network. This synthesis approach is based on the controlled self-assembly of growing polyelectrolyte microgel precursors during the precipitation polymerization process. We confirmed the morphology of polyampholyte Janus-like microgels and demonstrate that they are capable of responding quickly to changes in both pH and temperature in aqueous solutions.
Collapse
Affiliation(s)
- Wenjing Xu
- DWI—Leibniz-Institute for Interactive Materials e.V.RWTH-Aachen UniversityForckenbeckstraße 5052074AachenGermany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 252074AachenGermany
| | - Andrey Rudov
- DWI—Leibniz-Institute for Interactive Materials e.V.RWTH-Aachen UniversityForckenbeckstraße 5052074AachenGermany
- Physics DepartmentLomonosov Moscow State UniversityMoscow119991Russian Federation
| | - Alex Oppermann
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252074AachenGermany
| | - Sarah Wypysek
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252074AachenGermany
| | - Michael Kather
- DWI—Leibniz-Institute for Interactive Materials e.V.RWTH-Aachen UniversityForckenbeckstraße 5052074AachenGermany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 252074AachenGermany
| | - Ricarda Schroeder
- DWI—Leibniz-Institute for Interactive Materials e.V.RWTH-Aachen UniversityForckenbeckstraße 5052074AachenGermany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 252074AachenGermany
| | - Walter Richtering
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252074AachenGermany
| | - Igor I. Potemkin
- DWI—Leibniz-Institute for Interactive Materials e.V.RWTH-Aachen UniversityForckenbeckstraße 5052074AachenGermany
- Physics DepartmentLomonosov Moscow State UniversityMoscow119991Russian Federation
- National Research South Ural State UniversityChelyabinsk454080Russian Federation
| | - Dominik Wöll
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252074AachenGermany
| | - Andrij Pich
- DWI—Leibniz-Institute for Interactive Materials e.V.RWTH-Aachen UniversityForckenbeckstraße 5052074AachenGermany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 252074AachenGermany
- Aachen Maastricht Institute for Biobased Materials (AMIBM)Maastricht UniversityBrightlands ChemelotThe Netherlands
| |
Collapse
|
38
|
Bochenek S, Scotti A, Ogieglo W, Fernández-Rodríguez MÁ, Schulte MF, Gumerov RA, Bushuev NV, Potemkin II, Wessling M, Isa L, Richtering W. Effect of the 3D Swelling of Microgels on Their 2D Phase Behavior at the Liquid-Liquid Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:16780-16792. [PMID: 31782927 DOI: 10.1021/acs.langmuir.9b02498] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We investigate soft, temperature-sensitive microgels at fluid interfaces. Though having an isotropic, spherical shape in bulk solution, the microgels become anisotropic upon adsorption. The structure of microgels at interfaces is described by a core-corona morphology. Here, we investigate how changing temperature across the microgel volume phase transition temperature, which leads to swelling/deswelling of the microgels in the aqueous phase, affects the phase behavior within the monolayer. We combine compression isotherms, atomic force microscopy imaging, multiwavelength ellipsometry, and computer simulations. At low compression, the interaction between adsorbed microgels is dominated by their highly stretched corona and the phase behavior of the microgel monolayers is the same. The polymer segments within the interface lose their temperature-sensitivity because of the strong adsorption to the interface. At high compression, however, the portions of the microgels that are located in the aqueous side of the interface become relevant and prevail in the microgel interactions. These portions are able to collapse and, consequently, the isostructural phase transition is altered. Thus, the temperature-dependent swelling perpendicular to the interface ("3D") affects the compressibility parallel to the interface ("2D"). Our results highlight the distinctly different behavior of soft, stimuli-sensitive microgels as compared to rigid nanoparticles.
Collapse
Affiliation(s)
- Steffen Bochenek
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Andrea Scotti
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Wojciech Ogieglo
- Chemical Process Engineering , RWTH Aachen University , Forckenbeckstrasse 51 , 52064 Aachen , Germany
| | - Miguel Ángel Fernández-Rodríguez
- Laboratory for Soft Materials and Interfaces, Department of Materials , ETH Zurich , Vladimir-Prelog-Weg 1-5/10 , 8093 Zurich , Switzerland
| | - M Friederike Schulte
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Rustam A Gumerov
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Nikita V Bushuev
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation
| | - Igor I Potemkin
- Physics Department , Lomonosov Moscow State University , Moscow 119991 , Russian Federation
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50 , Aachen 52056 , Germany
- National Research South Ural State University , Chelyabinsk 454080 , Russian Federation
| | - Matthias Wessling
- Chemical Process Engineering , RWTH Aachen University , Forckenbeckstrasse 51 , 52064 Aachen , Germany
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstrasse 50 , Aachen 52056 , Germany
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials , ETH Zurich , Vladimir-Prelog-Weg 1-5/10 , 8093 Zurich , Switzerland
| | - Walter Richtering
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| |
Collapse
|
39
|
Xu W, Rudov A, Oppermann A, Wypysek S, Kather M, Schroeder R, Richtering W, Potemkin II, Wöll D, Pich A. Synthesis of Polyampholyte Janus‐like Microgels by Coacervation of Reactive Precursors in Precipitation Polymerization. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201910450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Wenjing Xu
- DWI—Leibniz-Institute for Interactive Materials e.V. RWTH-Aachen University Forckenbeckstraße 50 52074 Aachen Germany
- Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringerweg 2 52074 Aachen Germany
| | - Andrey Rudov
- DWI—Leibniz-Institute for Interactive Materials e.V. RWTH-Aachen University Forckenbeckstraße 50 52074 Aachen Germany
- Physics Department Lomonosov Moscow State University Moscow 119991 Russian Federation
| | - Alex Oppermann
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52074 Aachen Germany
| | - Sarah Wypysek
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52074 Aachen Germany
| | - Michael Kather
- DWI—Leibniz-Institute for Interactive Materials e.V. RWTH-Aachen University Forckenbeckstraße 50 52074 Aachen Germany
- Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringerweg 2 52074 Aachen Germany
| | - Ricarda Schroeder
- DWI—Leibniz-Institute for Interactive Materials e.V. RWTH-Aachen University Forckenbeckstraße 50 52074 Aachen Germany
- Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringerweg 2 52074 Aachen Germany
| | - Walter Richtering
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52074 Aachen Germany
| | - Igor I. Potemkin
- DWI—Leibniz-Institute for Interactive Materials e.V. RWTH-Aachen University Forckenbeckstraße 50 52074 Aachen Germany
- Physics Department Lomonosov Moscow State University Moscow 119991 Russian Federation
- National Research South Ural State University Chelyabinsk 454080 Russian Federation
| | - Dominik Wöll
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52074 Aachen Germany
| | - Andrij Pich
- DWI—Leibniz-Institute for Interactive Materials e.V. RWTH-Aachen University Forckenbeckstraße 50 52074 Aachen Germany
- Institute of Technical and Macromolecular Chemistry RWTH Aachen University Worringerweg 2 52074 Aachen Germany
- Aachen Maastricht Institute for Biobased Materials (AMIBM) Maastricht University Brightlands Chemelot The Netherlands
| |
Collapse
|
40
|
Karanastasis AA, Kenath GS, Sundararaman R, Ullal CK. Quantification of functional crosslinker reaction kinetics via super-resolution microscopy of swollen microgels. SOFT MATTER 2019; 15:9336-9342. [PMID: 31687735 DOI: 10.1039/c9sm01618j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Super resolution microscopy (SRM) brings the advantages of optical microscopy to the imaging of nanostructured soft matter, and in colloidal microgels, promises to quantify variations of crosslink densities at unprecedented length scales. However, the distribution of all crosslinks does not coincide with that of dye-tagged crosslinks, and density quantification in SRM is not guaranteed due to over/under-counting dye molecules. Here we demonstrate that SRM images of microgels encode reaction rate constants of functional cross linkers, which hold the key to correlating these distributions. Combined with evolution of microgel particle radii, the functional cross linker distributions predict consumption versus time with high fidelity. Using a Bayesian regression approach, we extract reaction rate constants for homo and cross propagation of the functional crosslinker, which should be widely useful for predicting spatial variations in crosslink density of gels.
Collapse
Affiliation(s)
- Apostolos A Karanastasis
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, USA.
| | - Gopal S Kenath
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, USA.
| | - Ravishankar Sundararaman
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, USA.
| | - Chaitanya K Ullal
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, USA.
| |
Collapse
|
41
|
Purohit A, Centeno SP, Wypysek SK, Richtering W, Wöll D. Microgel PAINT - nanoscopic polarity imaging of adaptive microgels without covalent labelling. Chem Sci 2019; 10:10336-10342. [PMID: 32110321 PMCID: PMC6984396 DOI: 10.1039/c9sc03373d] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/16/2019] [Indexed: 12/13/2022] Open
Abstract
Polymer nanostructures have enormous potential for various applications in materials and life sciences. In order to exploit and understand their full capabilities, a detailed analysis of their structures and the environmental conditions in them is essential on the nanoscopic scale. With a super-resolution fluorescence microscopy technique known as PAINT (Points Accumulation for Imaging in Nanoscale Topography), we imaged colloidal hydrogel networks, so-called microgels, having a hydrodynamic radius smaller than the diffraction limit, gaining unprecedented insight into their full 3D structure which is not accessible in this much detail with any other experimental method. In addition to imaging of the microgel structure, the use of Nile Red as the solvatochromic fluorophore allowed us to resolve the polarity conditions within the investigated microgels, thus providing nanoscopic information on the x,y,z-position of labels including their polarity without the need of covalent labelling. With this imaging approach, we give a detailed insight into adapting structural and polarity properties of temperature-responsive microgels when changing the temperature beyond the volume phase transition.
Collapse
Affiliation(s)
- Ashvini Purohit
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52074 Aachen , Germany .
| | - Silvia P Centeno
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52074 Aachen , Germany .
| | - Sarah K Wypysek
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52074 Aachen , Germany .
| | - Walter Richtering
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52074 Aachen , Germany .
| | - Dominik Wöll
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52074 Aachen , Germany .
| |
Collapse
|
42
|
Wypysek SK, Scotti A, Alziyadi MO, Potemkin II, Denton AR, Richtering W. Tailoring the Cavity of Hollow Polyelectrolyte Microgels. Macromol Rapid Commun 2019; 41:e1900422. [DOI: 10.1002/marc.201900422] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/12/2019] [Indexed: 01/03/2023]
Affiliation(s)
- Sarah K. Wypysek
- Institute of Physical ChemistryRWTH Aachen University 52056 Aachen Germany
| | - Andrea Scotti
- Institute of Physical ChemistryRWTH Aachen University 52056 Aachen Germany
| | | | - Igor I. Potemkin
- Physics DepartmentLomonosov Moscow State University Moscow 119991 Russian Federation
- DWI Leibniz Institute for Interactive Materials 52056 Aachen Germany
- Laboratory of Functional MaterialsNational Research South Ural State University Chelyabinsk 454080 Russian Federation
| | - Alan R. Denton
- Department of PhysicsNorth Dakota State University Fargo ND 58108‐6050 USA
| | - Walter Richtering
- Institute of Physical ChemistryRWTH Aachen UniversityJARA ‐ Soft Matter Science 52056 Aachen Germany
| |
Collapse
|
43
|
Ninarello A, Crassous JJ, Paloli D, Camerin F, Gnan N, Rovigatti L, Schurtenberger P, Zaccarelli E. Modeling Microgels with a Controlled Structure across the Volume Phase Transition. Macromolecules 2019; 52:7584-7592. [PMID: 31656322 PMCID: PMC6812067 DOI: 10.1021/acs.macromol.9b01122] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/20/2019] [Indexed: 12/13/2022]
Abstract
![]()
Thermoresponsive microgels are soft
colloids that find widespread
use as model systems for soft matter physics. Their complex internal
architecture, made of a disordered and heterogeneous polymer network,
has been so far a major challenge for computer simulations. In this
work, we put forward a coarse-grained model of microgels whose structural
properties are in quantitative agreement with results obtained with
small-angle X-ray scattering experiments across a wide range of temperatures,
encompassing the volume phase transition. These results bridge the
gap between experiments and simulations of individual microgel particles,
paving the way to theoretically address open questions about their
bulk properties with unprecedented nano- and microscale resolution.
Collapse
Affiliation(s)
- Andrea Ninarello
- CNR-ISC Uos Sapienza, Piazzale A. Moro 2, IT-00185 Roma, Italy.,Department of Physics, Sapienza Università di Roma, Piazzale A. Moro 2, IT-00185 Roma, Italy
| | - Jérôme J Crassous
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany.,Physical Chemistry, Department of Chemistry, Lund University, Naturvetarvägen 14, SE-22100 Lund, Sweden
| | - Divya Paloli
- Physical Chemistry, Department of Chemistry, Lund University, Naturvetarvägen 14, SE-22100 Lund, Sweden
| | - Fabrizio Camerin
- CNR-ISC Uos Sapienza, Piazzale A. Moro 2, IT-00185 Roma, Italy.,Department of Basic and Applied Sciences for Engineering, Sapienza Università di Roma, via A. Scarpa 14, IT-00161 Roma, Italy
| | - Nicoletta Gnan
- CNR-ISC Uos Sapienza, Piazzale A. Moro 2, IT-00185 Roma, Italy.,Department of Physics, Sapienza Università di Roma, Piazzale A. Moro 2, IT-00185 Roma, Italy
| | - Lorenzo Rovigatti
- Department of Physics, Sapienza Università di Roma, Piazzale A. Moro 2, IT-00185 Roma, Italy.,CNR-ISC Uos Sapienza, Piazzale A. Moro 2, IT-00185 Roma, Italy
| | - Peter Schurtenberger
- Physical Chemistry, Department of Chemistry, Lund University, Naturvetarvägen 14, SE-22100 Lund, Sweden
| | - Emanuela Zaccarelli
- CNR-ISC Uos Sapienza, Piazzale A. Moro 2, IT-00185 Roma, Italy.,Department of Physics, Sapienza Università di Roma, Piazzale A. Moro 2, IT-00185 Roma, Italy
| |
Collapse
|
44
|
Murray BS. Microgels at fluid-fluid interfaces for food and drinks. Adv Colloid Interface Sci 2019; 271:101990. [PMID: 31330395 DOI: 10.1016/j.cis.2019.101990] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/09/2019] [Accepted: 07/11/2019] [Indexed: 12/11/2022]
Abstract
Various aspects of microgel adsorption at fluid-fluid interfaces of relevance to emulsion and foam stabilization have been reviewed. The emphasis is on the wider non-food literature, with a view to highlighting how this understanding can be applied to food-based systems. The various different types of microgel, their methods of formation and their fundamental behavioral traits at interfaces are covered. The latter includes aspects of microgel deformation and packing at interfaces, their deformability, size, swelling and de-swelling and how this affects their surface activity and stabilizing properties. Experimental and theoretical methods for measuring and modelling their behaviour are surveyed, including interactions between microgels themselves at interfaces but also other surface active species. It is concluded that challenges still remain in translating all the possibilities synthetic microgels offer to microgels based on food-grade materials only, but Nature's rich tool box of biopolymers and biosurfactants suggests that this field will still open up important new avenues of food microstructure development and control.
Collapse
|
45
|
Minina ES, Sánchez PA, Likos CN, Kantorovich SS. Studying synthesis confinement effects on the internal structure of nanogels in computer simulations. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111066] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
46
|
Modena MM, Rühle B, Burg TP, Wuttke S. Nanoparticle Characterization: What to Measure? ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1901556. [PMID: 31148285 DOI: 10.1002/adma.201901556] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/19/2019] [Indexed: 05/20/2023]
Abstract
What to measure? is a key question in nanoscience, and it is not straightforward to address as different physicochemical properties define a nanoparticle sample. Most prominent among these properties are size, shape, surface charge, and porosity. Today researchers have an unprecedented variety of measurement techniques at their disposal to assign precise numerical values to those parameters. However, methods based on different physical principles probe different aspects, not only of the particles themselves, but also of their preparation history and their environment at the time of measurement. Understanding these connections can be of great value for interpreting characterization results and ultimately controlling the nanoparticle structure-function relationship. Here, the current techniques that enable the precise measurement of these fundamental nanoparticle properties are presented and their practical advantages and disadvantages are discussed. Some recommendations of how the physicochemical parameters of nanoparticles should be investigated and how to fully characterize these properties in different environments according to the intended nanoparticle use are proposed. The intention is to improve comparability of nanoparticle properties and performance to ensure the successful transfer of scientific knowledge to industrial real-world applications.
Collapse
Affiliation(s)
- Mario M Modena
- ETH Zurich, Department of Biosystems Science and Engineering, Mattenstrasse 26, 4058, Basel, BS, Switzerland
| | - Bastian Rühle
- Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter - Str 11, 12489, Berlin, Germany
| | - Thomas P Burg
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Merckstrasse 25, 64283, Darmstadt, Germany
| | - Stefan Wuttke
- Department of Chemistry, Center for NanoScience (CeNS), University of Munich (LMU), 81377, Munich, Germany
- BCMaterials, Basque Center for Materials, UPV/EHU Science Park, 48940, Leioa, Spain
| |
Collapse
|
47
|
Tuning the Swelling Properties of Smart Multiresponsive Core-Shell Microgels by Copolymerization. Polymers (Basel) 2019; 11:polym11081269. [PMID: 31370213 PMCID: PMC6722827 DOI: 10.3390/polym11081269] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 01/17/2023] Open
Abstract
The present study focuses on the development of multiresponsive core-shell microgels and the manipulation of their swelling properties by copolymerization of different acrylamides—especially N-isopropylacrylamide (NIPAM), N-isopropylmethacrylamide (NIPMAM), and NNPAM—and acrylic acid. We use atomic force microscopy for the dry-state characterization of the microgel particles and photon correlation spectroscopy to investigate the swelling behavior at neutral (pH 7) and acidic (pH 4) conditions. A transition between an interpenetrating network structure for microgels with a pure poly-N,n-propylacrylamide (PNNPAM) shell and a distinct core-shell morphology for microgels with a pure poly-N-isopropylmethacrylamide (PNIPMAM) shell is observable. The PNIPMAM molfraction of the shell also has an important influence on the particle rigidity because of the decreasing degree of interpenetration. Furthermore, the swelling behavior of the microgels is tunable by adjustment of the pH-value between a single-step volume phase transition and a linear swelling region at temperatures corresponding to the copolymer ratios of the shell. This flexibility makes the multiresponsive copolymer microgels interesting candidates for many applications, e.g., as membrane material with tunable permeability.
Collapse
|
48
|
Conley GM, Zhang C, Aebischer P, Harden JL, Scheffold F. Relationship between rheology and structure of interpenetrating, deforming and compressing microgels. Nat Commun 2019; 10:2436. [PMID: 31164639 PMCID: PMC6547648 DOI: 10.1038/s41467-019-10181-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 04/23/2019] [Indexed: 11/30/2022] Open
Abstract
Thermosensitive microgels are widely studied hybrid systems combining properties of polymers and colloidal particles in a unique way. Due to their complex morphology, their interactions and packing, and consequentially the viscoelasticity of suspensions made from microgels, are still not fully understood, in particular under dense packing conditions. Here we study the frequency-dependent linear viscoelastic properties of dense suspensions of micron sized soft particles in conjunction with an analysis of the local particle structure and morphology based on superresolution microscopy. By identifying the dominating mechanisms that control the elastic and dissipative response, we can explain the rheology of these widely studied soft particle assemblies from the onset of elasticity deep into the overpacked regime. Interestingly, our results suggest that the friction between the microgels is reduced due to lubrification mediated by the polymer brush-like corona before the onset of interpenetration.
Collapse
Affiliation(s)
- Gaurasundar M Conley
- Department of Physics, University of Fribourg, Chemin du Musée 3, 1700, Fribourg, Switzerland
| | - Chi Zhang
- Department of Physics, University of Fribourg, Chemin du Musée 3, 1700, Fribourg, Switzerland
| | - Philippe Aebischer
- Department of Physics, University of Fribourg, Chemin du Musée 3, 1700, Fribourg, Switzerland
| | - James L Harden
- Department of Physics, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada
| | - Frank Scheffold
- Department of Physics, University of Fribourg, Chemin du Musée 3, 1700, Fribourg, Switzerland.
| |
Collapse
|
49
|
Nishizawa Y, Matsui S, Urayama K, Kureha T, Shibayama M, Uchihashi T, Suzuki D. Non‐Thermoresponsive Decanano‐sized Domains in Thermoresponsive Hydrogel Microspheres Revealed by Temperature‐Controlled High‐Speed Atomic Force Microscopy. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201903483] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yuichiro Nishizawa
- Graduate School of Textile Science & Technology Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
| | - Shusuke Matsui
- Graduate School of Textile Science & Technology Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
| | - Kenji Urayama
- Department of Macromolecular Science and Engineering Kyoto Institute of Technology Sakyo-ku Kyoto 606-8585 Japan
| | - Takuma Kureha
- Institute for Solid State PhysicsThe University of Tokyo Kashiwanoha Kashiwa 277-8581 Japan
| | - Mitsuhiro Shibayama
- Institute for Solid State PhysicsThe University of Tokyo Kashiwanoha Kashiwa 277-8581 Japan
| | - Takayuki Uchihashi
- Department of Physics and Structural Biology Research CenterGraduate School of ScienceNagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
- Exploratory Research Center on Life and Living Systems National Institutes of Natural Sciences 5-1 Higashiyama, Myodaiji Okazaki Aichi 444-8787 Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology Shinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
- Division of Smart TextilesInstitute for Fiber EngineeringInterdisciplinary Cluster for Cutting Edge ResearchShinshu University 3-15-1 Tokida Ueda Nagano 386-8567 Japan
| |
Collapse
|
50
|
Nishizawa Y, Matsui S, Urayama K, Kureha T, Shibayama M, Uchihashi T, Suzuki D. Non-Thermoresponsive Decanano-sized Domains in Thermoresponsive Hydrogel Microspheres Revealed by Temperature-Controlled High-Speed Atomic Force Microscopy. Angew Chem Int Ed Engl 2019; 58:8809-8813. [PMID: 31056848 DOI: 10.1002/anie.201903483] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Indexed: 11/10/2022]
Abstract
Despite the tremendous efforts devoted to the structural analysis of hydrogel microspheres (microgels), many details of their structures remain unclear. Reported in this study is that thermoresponsive poly(N-isopropyl acrylamide) (pNIPAm)-based microgels exhibit not only the widely accepted core-shell structures, but also inhomogeneous decanano-sized non-thermoresponsive spherical domains within their dense cores, which was revealed by temperature-controlled high-speed atomic force microscopy (TC-HS-AFM). Based on a series of experiments, it is concluded that the non-thermoresponsive domains are characteristic for pNIPAm microgels synthesized by precipitation polymerization, and plausible structures for microgels prepared by other polymerization techniques are proposed.
Collapse
Affiliation(s)
- Yuichiro Nishizawa
- Graduate School of Textile Science & Technology Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan
| | - Shusuke Matsui
- Graduate School of Textile Science & Technology Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan
| | - Kenji Urayama
- Department of Macromolecular Science and Engineering Kyoto Institute of Technology, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Takuma Kureha
- Institute for Solid State Physics, The University of Tokyo, Kashiwanoha, Kashiwa, 277-8581, Japan
| | - Mitsuhiro Shibayama
- Institute for Solid State Physics, The University of Tokyo, Kashiwanoha, Kashiwa, 277-8581, Japan
| | - Takayuki Uchihashi
- Department of Physics and Structural Biology Research Center, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan.,Exploratory Research Center on Life and Living Systems National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan.,Division of Smart Textiles, Institute for Fiber Engineering, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-15-1 Tokida Ueda, Nagano, 386-8567, Japan
| |
Collapse
|